Mk4 Golf - Master cylinder cost

[3sixty]

Took my car into garage today to fix a leaking brake pipe. I came back from holiday last week and found a puddle on floor and brake fluid warning light.

The garage has replaced the pipe but said the pedal is still on floor. They said they think seals have gone on master cylinder. They said they tried to pressurise the system, but still didnt work so I'll need a new master cylinder.

Does this sound correct? And if so how much is it going to cost me in parts and labour?